COB leads new breakthroughs in small-pitch LEDs

Since its birth, the small-pitch LED screen has been continuously compressing its dot-pitch index. At present, domestic manufacturers have launched products with a pitch of 0.7 and 0.8 mm. However, this product has not been mass-produced and applied, and has encountered limits and ceilings in “marketization”. The further technological development of small-pitch LEDs is bound to depend on the progress and innovation of basic processes. COB technology is this new advanced process.

First of all, the COB small-pitch LED technology is conducive to the control of the dead pixel rate under the condition of extremely small spacing and extremely large number of lamp beads. With less than one-tenth of the dead pixel rate of the SMD surface mount process, it can achieve higher product reliability and realize the market application of high pixel density products. COB technology does my part.

Second, the COB technology that adopts the chip-level packaging process essentially replaces the two-step process of “surface-mount process first packaging into lamp beads and then surface-mounting” with packaging. As a more simplified engineering method, its cost change is more controllable under the same application scale, especially in the face of “smaller and smaller” pixels. That is, if the SMD surface mount can also rely on the price advantage on P1.5 pitch products, then on the P1.0 and below products, the cost advantage of SMD surface mount compared to COB will be reversed. This is the simplification of the entire engineering process, and the advantages brought by the direct mass packaging of LED crystals at the chip level.

Third, as the future development direction of the LED display industry, smaller crystal particles on small-pitch products are an unavoidable proposition. The advancement of LED light-emitting technology is enough to allow smaller LED crystal particles to have sufficient brightness, lower heat generation, and meet the needs of large displays. To integrate smaller LED crystal particles, it is obvious that COB packaging technology is more suitable than the traditional engineering route of “first lamp beads and then surface mount”.

As a manufacturer, when choosing a technical route, the future development space is a very important factor. The LED display screen is developing towards a smaller pitch, and the SMD technology encounters a bottleneck, while the COB technology has obvious advantages in realizing the small/micro pitch of the LED display screen. Vitron thinks so. In 2017, Samsung strengthened the promotion of small-pitch LED screens in the digital film projection market, and Sony increased the promotion of small-pitch LED screens in the production-level film and television market. Both giants are supporters of package-level technologies such as COB without exception. From the perspective of product research and development, in 2012, Sony demonstrated LED screen products based on MINI-LED particles, chip-scale packaging, and only 0.5 mm pitch. The LED upstream industry in Taiwan, my country, even believes that the “screen application” of MINI-LED products, including small-pitch LED screens and direct-type LCD backlight products, will enter the stage of accelerated development in 2018.

Even if it is a very good technology, it is impossible for COB small-pitch to occupy the entire market as soon as it comes up. It starts from the high-end and gradually becomes popular. This process has also been the “road” of surface-mount small-pitch LED large-screen products in the past 6 years. “. However, now it is the turn of COB small-pitch products to once again perform the “market iteration” process of first occupying the high-end and then popularizing.